Why are many lakes in the East African Rift System unusually deep?

The lakes within the East African Rift System are often unusually deep and fjordlike because they occupy the deep, narrow troughs created by the tectonic processes of the rift itself. As the African and Arabian plates have separated over the last 30 million years, the earth's crust has pulled apart, forming deep depressions that serve as basins for these lakes.1

While many of these lakes are remarkably deep—with some floors extending well below sea level—the depth of specific lakes can be influenced by other geological factors. For instance, the relative shallowness of some lakes, such as Lake Albert and Lake Edward, is attributed to the accumulation of thick layers of sediment on their floors. Additionally, volcanic activity has played a significant role in the region by shaping shorelines and blocking drainage patterns, which further dictates the formation and depth of these water bodies.12